Tumblr founder David Karp invests in medical start-up

Sherpaa, a New York-based start-up launched by medical doctor and entrepreneur Jay Parkinson, is making strides.

A big milestone was gaining the financial support of Dr. Parkinson's friend David Karp, founder and chief executive of Tumblr, now part of Yahoo, The Wall Street Journal reported. Tumblr, with a staff of 225 employees, is one of Sherpaa's early customers.